Table 2.
Estimates of baleen stable nitrogen isotope (δ15N) period and mean duration of gestation, interpeak, and calving intervals of individual bowhead whales. (Reproductive cycle parameters were estimated under two hypotheses: (H1) inclusive of total progesterone (P4) peak and (H2) inclusive of P4 peak up to final maxima. Immature whales were not included in this analysis. nd, not determined.)
| whale sample identity | δ15N period (cm yr−1) | H1: P4 total |
H2: P4 max |
calving interval (years) | ||||
|---|---|---|---|---|---|---|---|---|
| full P4 peak (months) | P4 1st phase (months) | P4 2nd phase (months) | interpeak interval (months) | gestation (months) | interpeak interval (months) | |||
| NSA-2011-03 | nd | nd | nd | nd | nd | nd | nd | nd |
| IG-HB-2002-001 | 20.2 | nd | nd | nd | nd | nd | nd | nd |
| NSA-2010-02 | 26.3 | nd | nd | nd | nd | nd | nd | nd |
| NSA-2009-02 | 14.4 | 25.0 | 10.8 | 14.2 | 43.3 | 19.2 | 49.2 | 5.7 |
| RB-2005-001 | 15.0 | 25.6 | 12.0 | 13.6 | 26.7 | 16.8 | 35.2 | 4.3 |
| 01-2009 | 16.0 | 24.0 | 11.0 | 13.0 | 13.9 | 14.3 | 23.3 | 3.1 |
| 500 | 15.9 | 21.6 | 10.0 | 11.6 | 20.0 | 15.5 | 26.0 | 3.5 |
| 325 | 16.0 | 22.0 | 10.0 | 12.0 | 18.0 | 16.0 | 24.0 | 3.3 |
| 501 | 17.9 | 22.8 | 8.3 | 14.5 | 12.1 | 15.4 | 19.1 | 2.9 |
| 502 | 17.4 | 24.0 | 8.0 | 16.0 | 12.4 | 16.0 | 20.0 | 3.0 |
| mean | 16.1 | 23.6 | 10.0 | 13.6 | 20.9 | 16.2 | 28.1 | 3.7 |